The long-term objectives of this program are to identify and characterize behavioral, pharmacological, and environmental factors that affect drug-taking behaviors. Ideally, we are seeking to establish the general principles that affect drug-taking behavior. The immediate goals of this project are five in number: (1) To identify and characterize the effects on operant behavior of narcotic agonists having different modes of action. (2) To identify the effects of chronic administration of the morphine- and kappa-type narcotics upon operant behavior with respect to the type and magnitude of tolerance and dependence development. (3) To determine interaction between narcotic-reinforced responding and narcotic dependence by studying the effects of narcotic deprivation and administration of narcotic antagonism under various behavioral and pharmacological preconditions. (4) To study aversive control by narcotic agonists in the presence of various degrees of narcotic dependence. (5) To study behavioral preparation using inhalation and intraventricular routes of narcotic self-administration.